November 15, 2013
New Cholesterol Treatment Recommendations
This week the American College of Cardiology and the American Heart Association released new guidelines for the treatment of high cholesterol. These new guidelines represent a revolutionary change in how patients will be selected for cholesterol-lowering medication and how that medication will be prescribed.
My regular readers (both of them) know well that the family of cholesterol-lowering medicines called statins have long been proven to prevent strokes and heart attacks. It is also well established that an elevated level of LDL cholesterol (“bad cholesterol”) increases the risk of stroke and heart attack. The previous guidelines recommended using statins to lower the LDL to certain specific goals which were lower for patients with higher stroke and heart attack risk. So it involved counting a patient’s risk factors, determining his LDL goal, and then increasing the statin dose until the goal was reached.
The problem with that approach is that there is no evidence that aiming for a specific LDL goal is helpful. We know taking a statin helps, but there is no reason to believe that dialing the dose up or down based on the LDL gives the optimal results.
To understand why this might be the case, let’s think of a couple of other examples. Aspirin is a blood thinner that is well-known to prevent strokes and heart attacks. But the benefit doesn’t depend on measuring anything. Meaning we don’t need to check how thin the blood is to know that the medicine is effective. Everyone gets the same dose (more or less) and that’s that. The same dynamic is present when we prescribe antibiotics for an infection. The dose might be calculated based on the patient’s weight (especially for children) but the dose isn’t adjusted based on the patient’s clinical improvement or worsening. The standard dose is given and is known to be the effective dose.
Statins are slowly moving in that direction. Taking the medicine is known to help, and the goal isn’t reaching a lower cholesterol number; the goal is not having a stroke or a heart attack.
Rather than focusing on which cholesterol levels should receive cholesterol-lowering medications, the new guidelines focus on which patients are most likely to benefit. The guidelines recommend statin treatment for the following four groups of patients.
• Patients who have symptomatic cardiovascular disease. That is, patients who have had a heart attack, a stroke or transient ischemic attack (temporary stroke), angina (chest pain due to narrowing in coronary arteries), bypass surgery or angioplasty, and patients with symptomatic narrowing in any arteries in the body.
• Patients with LDL cholesterol over 190. These patients usually have a genetic cause of their high cholesterol and are at very high risk of stroke and heart attack.
• Patients between the ages of 40 and 75 with diabetes and LDL cholesterol between 70 and 190.
• Patients between the ages of 40 and 75 with LDL cholesterol between 70 and 190 and a risk of stroke and heart attack over the next 10 years of 7.5% or more. A spreadsheet that calculates this risk is available and requires you to know your most recent cholesterol panel and blood pressure.
This last criterion will likely apply to many men in their 50s and women in their 60s, vastly expanding the number of people taking statins.
The new recommendations also state that non-statin cholesterol-lowering medications like niacin and Zetia should not be routinely used since the evidence that they prevent strokes and heart attacks is scant or nonexistent.
The new recommendations have generated some criticism. Some experts claim that they are too complex. Others bemoan the number of people that will now be offered statins. I think the recommendations are actually simpler than what we were doing before. I’m sure we’ll all need some time to get used to them and understand the fine points. My impression is that patients will be able to apply these recommendations much more easily and see for themselves how they compare to the various treatment groups.
As to the criticism that statin use will dramatically increase, if this leads to marked declines in the numbers of strokes and heart attacks then this is not a criticism of the new guidelines but a major improvement over the prior recommendations.
Experts Reshape Treatment Guide for Cholesterol (New York Times)
Important legal mumbo jumbo: